How much does a 2018 MERCEDES G-CLASS cost to run?

Estimated annual running cost is £1,695 (£141/month), including £1245 fuel, £195 road tax, £55 MOT, and £200 predicted repairs.

What is the MOT pass rate for a 2018 MERCEDES G-CLASS?

The 2018 MERCEDES G-CLASS has a 94% MOT pass rate based on 807 tests in 2026. This ranks 135 out of 649 cars from 2018.

Which year MERCEDES G-CLASS is most reliable?

The 2020 MERCEDES G-CLASS has the highest MOT pass rate at 98%. The least reliable year is 2021 at 78%.

MERCEDES G-CLASS (2018)

Q: Is the 2018 MERCEDES G-CLASS reliable?

Excellent reliability. Very few MOT failures. 94% of MERCEDES G-CLASSs from 2018 passed their MOT first time in 2026, based on 807 tests. That's 12 points above the national average of 82%.

Q: What is the average mileage for a 2018 MERCEDES G-CLASS?

The average mileage for a 2018 MERCEDES G-CLASS is 39,199 miles, which is below the expected 59,200 miles for a 8-year-old car. This suggests lighter use than average, which generally means less wear on major components.

Running costs, reliability data, and common problems from 807 real MOT tests.

Annual Cost

£1,695

£141/month

MOT Pass Rate

94%

Excellent

Road Tax

£195

Flat rate/year

Insurance

Grp 30-42

2987cc Diesel

Great Choice

94% pass rate, £1695/year to run. 12 points above average.

Buying this car? Check for finance, write-offs & theft

£4.99

Check a specific MERCEDES G-CLASS

Enter a reg plate for full MOT history, mileage check, health score, running costs, and reliability data. Free, instant, no signup.

Diesel2987cc8 years old807 tests39k miles avg

Annual Running Costs

Fuel (Diesel, 2987cc)

~40 mpg

£1,245

Road Tax

Flat rate (post-2017)

£195

MOT Test

£55

Predicted Repairs

Low estimate due to excellent reliability

£200

Total per year£1,695

Per month£141/mo

Per week£33/wk

Based on 7,400 miles/year (UK average), current fuel prices, and repair likelihood from MOT data. Insurance not included.

🛡️

Get an insurance quote for this MERCEDES G-CLASS

Compare quotes and find the best deal

Reliability Verdict

94% MOT pass rate(Excellent)

0%National avg: 82%100%

Excellent reliability. Very few MOT failures. That's 12 points above the national average of 82%. It also outperforms the MERCEDES brand average of 87%.

At 8 years old, 94% of MERCEDES G-CLASSs from 2018 passed their MOT first time in 2026. That's based on 807 tests across the UK. The average mileage at this age is 39,199 miles.

Got a MERCEDES G-CLASS you're looking at?

Enter the reg plate to check its specific MOT history, mileage, and health score.

How Does It Compare?

Rank among 2018 cars135th of 649(top 21%)

Rank among MERCEDES models301th of 1,408(top 21%)

vs national average+12%(82% avg)

vs 2018 cars average+5%(89% avg)

vs MERCEDES average+7%(87% avg)

Mileage Analysis

39,199

Average miles

59,200

Expected for age

The average 2018 MERCEDES G-CLASS has 39,199 miles on the clock, which is below the expected 59,200 miles for a 8-year-old car. This suggests lighter use than average, which generally means less wear on major components.

Looking at a specific MERCEDES G-CLASS?

Enter its reg plate for a free check with full MOT history, mileage verification, and predicted costs.

Best Year to Buy?

The most reliable year is the 2020 model with a 98% MOT pass rate, while the 2021 model has the lowest at 78%. The 2018 sits between the two at 94%.

MERCEDES G-CLASS by Year

Year	Pass Rate	Tests	Avg Mileage
2021	78%	65	30,190 mi
2020	98%	66	32,570 mi
2019	96%	319	41,698 mi
2018	94%	807	39,199 mi
2017	86%	691	43,730 mi
2016	94%	604	58,012 mi
2015	88%	591	48,991 mi
2014	92%	362	54,969 mi
2013	94%	449	69,675 mi
2012	90%	221	76,209 mi
2011	96%	92	70,666 mi
2010	73%	33	78,145 mi
2007	100%	35	103,461 mi
2001	60%	42	93,234 mi
1999	82%	44	113,541 mi

Similar Cars to Consider

MERCEDES E

2019 · 2925cc Diesel

£1,690/year

90%

-4%

MERCEDES GLC

2018 · 2987cc Diesel

£1,690/year

91%

-3%

AUDI A5

2017 · 2967cc Diesel

£1,840/year

89%

-5%

FORD RANGER

2019 · 3198cc Diesel

£1,840/year

87%

-7%

Check a Specific Mercedes G-class

Enter a reg plate to get the full MOT history, health score, and mileage verification.

Upgrade to Premium (£4.99) for stolen, finance, and write-off checks.

About the 2018 MERCEDES G-CLASS

The 2018 MERCEDES G-CLASS is a large car with a 2987cc diesel engine. 807 of these vehicles were MOT tested in 2026, making it a less common model in the UK market. It ranks in the top 21% of all 2018 cars for reliability.

With an average of 39,199 miles at 8 years old, MERCEDES G-CLASS owners tend to use this car less than the typical driver.

2018 MERCEDES G-CLASS Fuel Costs

The 2987cc diesel engine is on the larger side, so fuel won't be this car's strong point. Expect around 40 mpg in mixed driving, which works out to roughly £1,245 per year at current diesel prices of 148p per litre (based on 7,400 miles per year). Diesel cars of this age should have their DPF (diesel particulate filter) checked, as replacements can be costly.

What does it cost to own a 2018 MERCEDES G-CLASS?

Total estimated annual running cost is £1,695 (£141/month), broken down as £1245 fuel, £195 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 94% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.

MERCEDES G-CLASS Reliability Trend

The MERCEDES G-CLASS has maintained consistent MOT pass rates across model years, varying by only 1 percentage points.

Buying a Used 2018 MERCEDES G-CLASS

At 8 years old, this is a solid used buy if you find one with good service history. Depreciation has levelled off, so you won't lose much more value. Focus on condition over mileage. If you're flexible on year, the 2020 model has the highest pass rate at 98%.

Common Issues to Watch For

Based on the 2018 MERCEDES G-CLASS's fuel type, age, and engine size, these are the most likely problem areas to check.

DPF (Diesel Particulate Filter)

Watch out

Short journeys clog the DPF. Replacement costs £1,000-£2,500. Check the DPF warning light and ask about driving patterns.

Turbo Wear

Watch out

Diesel turbos work harder and wear faster. Listen for whining noises and check for oil leaks around the turbo housing.

AdBlue System

Medium risk

Post-2015 diesels use AdBlue for emissions. Sensor failures and tank heater issues are common. Budget £200-£500 for repairs.

EGR Valve

Watch out

Exhaust Gas Recirculation valves clog with carbon deposits, causing rough running and poor economy. Cleaning costs £150-£300, replacement £300-£600.

Dual Mass Flywheel

Watch out

Larger diesel engines put extra strain on the dual mass flywheel. Listen for rattling at idle. Replacement with clutch is £800-£1,500.

Suspension Wear

Medium risk

Shock absorbers, springs, and anti-roll bar links typically need attention around this age. Listen for clunks over bumps and check for uneven tyre wear.

Service History

Low risk

Always request a full service history. Regular servicing is the single best indicator of how well a car has been maintained, regardless of mileage.

Running Costs Compared

How the 2018 MERCEDES G-CLASS stacks up against similar cars for annual running costs, insurance, and tax.

Car	Pass Rate	Fuel/yr	Tax/yr	Insurance	Total/yr
MERCEDES G-CLASS(2018)	94%	£1245	£195	Grp 30-42	£1695
MERCEDES E(2019)	90%	£1245	£190	Grp 30-42	£1690-£5
MERCEDES GLC(2018)	91%	£1245	£190	Grp 30-42	£1690-£5
AUDI A5(2017)	89%	£1245	£190	Grp 30-42	£1840+£145
FORD RANGER(2019)	87%	£1245	£190	Grp 35-50	£1840+£145

Estimates based on 7,400 miles/year, current fuel prices, and MOT data. Insurance groups are indicative. Actual costs vary by driver, location, and usage.